So far it has been quite troublesome to lift a vehicle by an underground lift which uses attachments for directly supporting the bottom of a vehicle. Firstly, the conventional attachments used for this purpose are not easy to handle because they themselves are sliders which can be removably set in a guide member and, hence, they are quite heavy in weight. Secondly, the conventional attachments, or sliders, are manually moved toward or away from each other. No hydraulic, pneumatic or electric mechanism has been provided to move the sliders. Thus, it has been necessary for a repairman to crawl under the vehicle and manually move the sliders to positions where the sliders can support the vehicle safely.